Process for purifying hydrocarbon oils



Mai 26, 1936.

c. o. HOOVER PROCESS FOR PURIFYING HYDROGARBON O ILS Original Filed Sept. 9, 1952 Patented May 26, 1936 UNITED STATES.

PROCESS FOR PG .HYDBO- CARBON OELS Charles Hoover, SanAntonio, Tex., assignor to Bennett-Clark 00., Inc., San Antonio, Tex.,

a corporation of Texas September 9, 193a, Serial No. 632,402

February 10, 1936 Applicatio 5 Claims. ('01. 196-29) dioxide or other acid compounds containing sulphur. y I

The process is especially useful in the case of treating naphthas, raflinate, gasoline and kerosene and similar like fractions containing sul-'- phur compounds existing in said oilsin the form of organic sulphur compounds and is especially useful in treating naphthas, raflinate, gasoline, kerosene and similar products containing organic sulphur compounds in the form of mercaptans, although the process is also applicable to the treatment of hydrocarbon oils generally which contain said sulphur compounds.

In general, the present. invention relates to process for sweetening sour hydrocarbcmoils.

An objectof the present invention is to provide a process by which the sour compounds in-sour oils or distillates may be removed or altered, or

converted into compounds which are not sour,.

thus rendering the souroils or distillates sweet, and in which process, if desired, the agent or agents employed to sweeten the sour oilsor distillates may be reactivated or regenerated concurrently with their use in. the. sweetening of the. sour oils' or distillates, whereby the sweetening oi the sour oils or distillates and the maintenance of the activity of said agent or agents may be effected at the same time.

v A further object of the invention is the pro.- vision of a process by which sour oils may the sweetened without the use of the so called doctor solution", that is an aqueous solutionpf sodium plumbite, and also without the use of aqueous solutions of salts of metals forming insoluble sulphides with hydrogen sulphide, such as aque-- oussolutions of cupric chloride or other cupric salts. J

Oils treated in accordance with the process of the present invention are not only doctor-sweet after treatment, but the oils also after treatment by the process of the present invention frequently show a lowered gum content or pass a more satisfactory corrosion test or both. many in- -phide or sell it for whatever can be obtained stances also the color and stability of the color of the oil treated is improved. a

The removal of mercaptans from 0115' of the character described by the use of doctor solution,

or aqueous sodium plumbite solution, is well understood in the art and the removal is accomplished by intimately contacting the aqueous sodium plumbite .or doctor solution with the oil to be sweetened or from which the mercaptans are to be removed. The sodium plumbite reacts with the mercaptans to produce lead mercaptides and these are in turn decomposed by elemental sulphur added to the oil treated either before, after or during the treatment with the doctor or sodium plumbite solution. The elemental sulphur reacts with the .lead ,mercaptides and produces organic disulphides and lead sulphide. The actual number of grams or pounds of sulphur in the oil combined as the mercaptans lsnot reduced by the treatment with the doctor or -plumbite solution, but-it is changed into a form that is not sour and relatively stable, that is if R represents the organic radicals of the mercaptans the change is from two molecules of mercaptans, 2RSH, to one molecule of disulphide,. RSSR. The plumbite or doctor solution process of treating sour oils is objectionable in many respects requiring sulphur, large quantities of litharge and caustic alkali for the production of the aqueous sodium plumbite solution and is considerably expensive, since the lead of the lead sulphide is lost unless it is recovered by smelting operations or converted into sulphate or oxide by some suitable process. in available form for reuse is not generally done by refiners and many refiners, on account of the cost of recovering the lead in available form from the lead sulphide, find it more advantageous to purchase fresh litharge and discard the lead sulfor it. a

The plumbite treatment is further objectionable in that oils which before treatment exhibited a satisfactory corrosion test are likely aiter treatment to exhibit an unsatisfactory corrosion test, and the oils treated usually have their total sulphur content increased. A still further objection The recovery of the lead of the plumbite treatment of sour oils is the fact that the insoluble lead sulphide formed in the oil when sweetened with aqueous doctor solution or 55,

insoluble sulphides with hydrogen sulphide, as for example a water solution of cupric chloride, when rerun, that is when they are redistilled, produce distillates which are sour to the "doctor test" notwithstanding that the oils have been sweetened before distillation by intimate contact with aqueous doctor solution or water solutions of said salts. This is an objection which is overcome by the process of the present invention, since oils treated in accordance with the present invention upon being re-run or redistilled yield distillates which are usually, if not always, sweet to the doctor test.

A further object of the present invention is the provision of a process by which sour oils can be treated and sweetened at a very rapid rate and at a very nominal cost, as the agent or agents ac- :etc. colorations to oils containing a high proportion complishing the sweetening action may be regenerated for continued use.

A further object of the present invention is to provide a sweetening process which includes reactivating or regenerating materials or compounds after they have been used therein to sweeten sour hydrocarbon oils and distillates.

A still further object of the present invention is the provision of a process for sweetening sour hydrocarbon oils in which the agents used in producing sweetening may be employed substantially in the absence of water, or, at any event, not in the form of a water solutio'mwhereby the efiects of water solutions of compounds, salts or agents, or suspensions thereof in water, in producing corrosion of the equipment or objectionable suspensions in the oils undergoing treatment are avoided.

'According to the present invention mineral or hydrocarbon oils, for example gasoline, naphthas, raifinate, water whites-furnace oils, diesel engine oils, transformer oils, kerosene, or heavier oils than these, containing mercaptans as sour constituents, which are to be sweetened, are brought fullers earth or bentonite or like clays. Examples of specific metal compounds which may be employed are cupric oxide, cupric hydroxide, cupric chloride, cupric nitrate, basic cupric carbonate, mercuric chloride, ferric chloride, ferric sulphate Iron compounds usually give objectionable of unsaturated hydrocarbon compounds and for that reason should not be-used in treating such oils when an uncolored product is desired. Cupric chloride may advantageously be used in treating naphthas, rafiinate or gasolene or other. oils containing high proportions of unsaturated hydrocarbon compounds. In addition to the clay and metal compound an oxidizing agent may be as sociated therewith such as alkali permanganates, as potassium permanganate or manganates, manganese dioxide or other oxidizing agent. According to the present preferred mode of practicing my invention the metal compounds, such as cupric oxide, cupric hydroxide, cupric chloride,-

. I with water solutions of salts of metals forming cupric nitrate, basic cupric carbonate, mercuric 'myself to this specific manner of accomplishing V the said regeneration, as other modes of accomplishing the regeneration are within my invention, as more fully set forth below.

Very satisfactory results may be obtained by utilizing a mixture comprising from '70 to 98 per cent clay with from 30% down to 2%, and even less, of 15 metal compound as for example cupric chloride. An oxidizing agent may be mixed into the mixture of clay and metal compound to the extent of about 245%, for example 5% of potassium per manganate. The reagents in the mixture, including the clay, preferably should be in a fine state of division, preferably completely passing through a 100 mesh screen and most of it passing through a 200 mesh screen, Very satisfactory results are produced by using a. reagent mixture containing of dry clay, 5% of cupric chloride and 5% of potassium permanganate. A satisfactory mixture also consistsof dry clay and 5% cupric chloride. The mixtures of clay and metal com- .pound, or mixtures of clay, metal compound and oxidizing agent are used in a dry powdery condition, such as would be obtained by mixing finely divided dry clay andfinely divided dry metal compounds of the kind indicated above, and finely divided dry clay, finely divided dry metal compounds and finely divided dry oxidizing agent. When the metal compounds are used alone, without addition of clay or oxidizing compounds, the said metal compounds are used also in a finely divided dry condition. Water of crystallization in the metal compounds or oxidizing compounds is not objectionable. The presence of a slight amount of water is not particularly disadvantageousibut the amount of water should not reach such an extent as to form a solution phase or as to form a. muddy mass with the clay or other linely divided adsorbent. The practical limits to which water may be present in the practice of the process are considered below. Thus, in the beginning of the practice of the invention the metal compounds and oxidizing compounds are present in association with the clay or other adsorbent in the solid or substantially dry condition and the clay or other adsorbent is also substantially dry.

The metal compound or mixture of metal compound and clay, with or without added oxidizing agent, maybe agitated in any suitable way 'with the "sour oil, naphthas or gasolene etc. and air or oxygen intimately contacted with the mass being agitated. After agitation of the naphthas, gasolene or kerosene 'etc. in presence of air or oxygen and the metal compounds or metal, compounds and clay, the metal compounds and clay are allowed to settle from the sweetened naphthas, gasolene or kerosene, etc. and the said settledmetal compounds, or metal compounds together with the clay associated therewith, are again agitated with sour" naphtha, gasolene or kerosene etc. in the presence of air or oxygen to produce sweetening of the oils.

In carrying out this use and re-use of reagents,

the reagents sour naphthas, gasolene or kerosene pletely sweetened on passing through the centrifugal pump. The mixture may then be led to a. point about midway of the height of a. tall tank where the reagents and clay will settle from the sweet naphthas, gasolene or kerosene etc.

into the tank as above described. Sweet oil will accumulate in the upper portion of the 'tankfree of metal compound and clay, and may be drawn off continuously or intermittently. The centrifugal pump may be operated intermittently or continuously in its aspiration of reagent and clay from the tank and in its mixing-of the reagents and air with thesour oil and discharging of the mixture into the tank.

I have found it advantageous to add a small amount of an acid to the oil undergoing treatment. The acid is preferably one which contains the negative radical of the metal compound. Thus in the case of cupric chloride it would be hydrochloric acid, in the case of cupric nitrate it would be nitric acid, and sulphuric acid for sulphates. This addition of acid inmany cases increases the degree and rate of regeneration; This additional acid is required in those ases where on account of the acidic character of he salt or metal compounds in the presence f water or moisture acid is removed by reaction with the basic constituents of the clayemployed or absorbed as acid by the clay. As understoodqby the person skilled in the art, the amount ofacid to be. added will depend upon a number of factors including the character of the clay, the degree of hydrolysis of the salt and all of which may be readily ascertainable, if not by computation, then by trial.

The drawing accompanying the present application shows schematically apparatus suitable for use in practicing the invention. Referring to the drawing the numeral l indicates a centrifugal pump. The numeral 2 indicates a settling tank. The discharge end of the centrifugal pump is connected with the settling tank 2 by means of a pipe 3, the pipe 3 discharging into the tank 2 about midway of its height. The numeral 4 indicates a line from which the sour oil to be treated is taken. The tank 2 is conically shaped at its bottom and discharges from its bottom into a pipe 5 which connects with apipe 6 which leads to the inlet side of the centrifugal pump I, the

pipe 6 forming a continuation of the pipe 4. A

hopper 1 is connected by means of a pipe 8 to the pipe 6 for introd icing into the pipe 6 the metal compound or clay and metal compound mixtures described above. A pipe 9 connects with the pipe 6 for introducing air or oxygen into the pipe 6 leading to the inlet of the centrifugal pump I. The air or oxygen is preferably dry. Hydrochloric acid, preferably as dry hydrochloric acid gas, is introduced into the pipe 6 by means of the pipe iii. A pipe I I may be connected with the pipe 3 to discharge oil into the hopper I to facilitate the discharge of clay and reagent from the hopper I into the pipe 6. To the upper end of the tank 2, or near its upper end, is connected a discharge pipe I2 for the treated product. A strainer or filter i3 may be connected with the discharge pipe l2 to remove any entrained metal compound, clay, or suspended matter in the oil treated. This strainer is not usually necessary, since if the outlet of the tank 2 for the pipe I2 is sufficiently high above the discharge point of the pipe 8 intothe'tank and the discharge outlet of the pipe .3sufllciently large to slow down sufllciently the velocity of the oils entering the tank, the clay and metal compound mixtures will completely settle from the oils before the oils are discharged through the pipe l2. The numeral l4 indicates valves for suitably controlling the flow in the various pipes. A pipe l5 also connects with the discharge from the centrifugal pump I, the purpose'of said pipe I5 being to enable the system or apparatus to be emptied.

In operation the sour oil to be treated enters from the pipe 4 into the pipe 6 where it is mixed with hydrochloric acid and air respectively en- "itering'the pipe 6 from the pipes l0 and 9. The

the centrifugal pump l and the mixture is discharged through the pipe 3 into the tank 2 where the clay-cupric chloride mixture settles from the oil in the conical portion of the tank 2. The settled clay-cupric chloride mixture with some oil is then redrawn into the pipe 8 through the pipe Sunder the action of the pump for treating further quantities ofsour oil.

The treated or sweet oil is withdrawn from'the tank 2 by means of the pipe l2, and, if necessary, passed through a strainer I3 to remove suspended matter. When air is introduced through the pipe 9, nitrogen will also escape with the oil passing out through ii.

For a naphtha containing 44 milligrams mercaptans per cubic centimeters of naphtha and containing 0.060% total sulphur and.5.0 milligrams gums (by copper dish method) per 100 cubic centimeters oil, it has been found that 25 barrels of such an oil may be circulated in the apparatus shown with pounds of a clay mixture' containing 95% clay and 5% cupric chloride and the sweetened oil withdrawn at l2. The sweetening is substantially fully accomplished after the mixture of oil and reagents has passed through the centrifugal pump 0. I

As the oil to be treated enters the circulating body of oil and reagents from the pipe d, the treated oil is withdrawn through the pipe l2. The clay-cupric chloride mixture is thus continuailly re-circulated with oil to be treated.

The clay-cupric chloride mixture seems to be utilizable as long as it is practically possible to circulate it with the oil under treatment 'inthe apparatus shown. The conversion of the mercapare formed in the apparatus shown, the said pellets then being considerably smaller than mustard seed. The air, oxygen, or oxygen containing gas, which is used to regenerate or-reactivate the metal compounds or mixtures used to sweeten the sour oils, also acts to considerably retard the formation of these pellets. The air or oxygen or oxygen containing gas also prevents certain objectionable colorations from occurring in the oils treated which would otherwise be the case if oxygen were not used. This is especially true where cupric salts or mixtures of cupric salts and adsorbents are employed, for example amixture of 95% clay and 5% supric chloride. Adsorbent, such as fullers earth or clay, also assists in preventing these objectionable colorations.

Before this stage of pellet formation is reached, for example when the moisture or water content of the clay is about 9 per cent, the settled clay mixture in the tank 2 may be withdrawn by pumping it out through the pipe 15, and the so withdrawn clay mixture, which is in the form of a slurry with oil, is subjected to a drying operation in order to reduce the moisture or water content, whereupon the clay mixture may be used again for treating further quantities of oil until the water concentration builds up again to an objectionable degree, after which the clay mixture may be again freed of moisture or water by drying and used over again.

The drying of the-clay mixture slurry may be accomplished by spreading the slurry out in thin layers and permitting the oil and moisture to evaporate, either with or without the application of heat. When treating raflinates, the slurry of raflinate and clay mixture is advantageously dried by distillation under reduced pressure at a temperature preferably not exceeding 200 F. The vacuum employed with this temperature is .about 28 inches or an absolute pressure of 1.92

inches. Heat and vacuum may be similarly applied to dry the clay mixtures when used to sweeten other .oils besides rafilnates.

In the above described processes of treating mineral oils, finely divided kieselguhr, pumice, calcium silicate, porous earthenware, and other non-adsorbent materials may be substituted in whole or in part for the clays above described. Other adsorbents such as active carbon or silica gel may be substituted in whole or in part for the adsorbent or absorbent clay.

The gasoline or other oils containing .mercaptans or other organic sour constituents are sweetened by treatment according to the present process. The mercaptans which are the principal sour constituents are changed into organic disulphides of the type R,SSR in the sweet gasoline. As a result of this conversion of mercaptans into disulphides, acid (as hydrochloric acid when using cupric chloride) appears to arisewhich would otherwise be found present in the treated gasoline or other oil were it not for the presence of .the clay which appears to retain the acid and prevents it from contaminating the sweetened material. The clay has the further action of retaining the acid so that it may be present in contact or in association with the metal compound so that the oxygen or air used to accomplish the regeneration may better accomplish its function. The organic disulphides arise because of the oxidation of the mercaptans in the sour oils to disulphides and water, which small amount of water either remains in solution in the oil treated or is taken up by the clay. This oxidation action, where polyvalent metal compounds are employed, is accompanied by a reduction in the valency or degree of oxidation of the metal, which is restored again to a higher valency or maintained in a higher valency or state of oxidation by the air or oxygen which is. introduced into the apparatus through the pipe 9.

The chemical actions taking place in the process utilizing a metal compound, an adsorbent and oxygen, air or other oxidizing agent will more fully appear from the following explanations,

using cupric chloride, fullers earth and oxygen,

the extent that it has reacted with the sour con-- stituents; these mercaptides (organic sulphur .metal compounds) are removed from the oil, or

caused to disappear therefrom, by the actionof the fullers earth (the adsorbent material), and the oxygen which is added over and above any naturally occluded in the fullers earth (adsorbent material) maintains, renews or continues the activity of the cupric chloride (metal compound) to sweeten the sour. oil, that is to say regenerates what is spent, as well as continues or maintains the activity of the fullers earth (adsorbent material) to remove or cause the disappearance of mercaptides (organic sulphur metal compounds). The net result of the actions-may, therefore, be considered as carrying of oxygen to the mercaptans or sour constituents to oxidize them.

The amount of air or oxygen introduced into the pipe 6 through the pipe 9 must besuflicient to accomplish the regeneration of the reagents employed. Roughly it might be said that the quantity required must be sufficient to keep the metal compounds used in their higher valency condition. An excess of air or oxygen appears to be without harmful influence on the treatments of the oils. For example, in the case of cupric chloride, enough air or oxygen must beused to keep the cupric chloride in the cupric condition. The dry hydrochloric acid gas added through the pipe I0 is added in suflicient quantity to make up contrary is beneficial, improving the color and color stability of the sweetened oil.

In cases where the oil or material to be treated contains considerable amounts of hydrogen sulphide in addition to the mercaptans it is preferable to intimately contact the material with an aqueous caustic soda solution, or any other suitable agent, for the purpose of removing the hydrogen sulphide. In the case of treating naphtha's, gasolenes or kerosenes, etc., as now prepared by refineries it is not usually necessary to employ this caustic alkali treatment as a preliminary step 'to the process of the present invention, for the reason that the naphtha; gasolene or kerosene, etc., is usually during its prepapheric temperatures,.at which temperatures the 75 reagents (such as cupric chloride, etc.) would normally react with vmercaptans to form mercaptides and which temperatures are below the point at which mercaptides'would be decomposed by heat; although it is to be understood that the present invention also applies to oils which may be heated to a point considerably above ordinary atmospheric temperatures but below their boiling points, so long as a temperature below the decomposition temperature of meroaptides is used. The oils also may be treated under pressure eit er at atmospheric temperatures or higher te peratures indicated above. It is a well known fact that hydrocarbon or mineral oils and distillates thereof are usually stored or collected in large tanks in the open and subject to all changes in atmospheric temperatures, and the terms "atmospheric temperatures or "atmospheric temperature as used herein are intended to include temperatures within the range of temperatures towhich such oils and distillates may be subjected while ,contained in tanks exposed to the atmosphere.

The invention may be applied to the treatment of pressure distillates, distillates resulting from the cracking of petroleum oils, or to the treatmeans of the centrifugal pump while oxygen or air is added thereto through the pipe 9 with or without the introduction of hydrochloric acid through the pipe. 10. Or the slurry of oil with ment of straight run distillates from petroleum 1 or treated with any aqueous solution, the water or aqueous solution should be allowed to coma 40 pletely settle from the oil, and the oil only when separated from water or aqueous solution used for practicing the invention. A very small amount of water within the limits explained above are not objectionable, nor does any water which may be dissolved in the oil treated impair the operation of the process.

Instead o5 utilizing the metal compounds such as cupric-oxide, cupric hydroxide, cupric chloride, cupric nitrate, basic cupric carbonate, mercuric chloride, ferric chloride, ferric sulphate,

etc., in the higher valency in the beginning of the treatment of the oils to sweeten them, these compounds may be employed in the beginning in the lower valencies or in the -ous condition and brought upto the higher valency or -ic condition during the practice of the invention through the oxidizing action of the oxidizing agent introduced into the oil undergoing treatment or through the oxidizing agents added to the metal compounds or mixtures of metal compounds and adsorbents;

while the sweetening agents employed are preferably regenerated or reactivated or maintained in the active conditions concurrently withv the .65 sweetening action, it is to be understood-that the sweetening agents or mixtures described herein may be regenerated or reactivated as a separate step. For example, the sour oils may first be treated with the sweetening reagents or mixtures 70 of sweetening reagents and adsorbent material and after they have become partially or wholly spent, the slurry of oil and the sweetening agents or the slurry of oil with the mixtures of sweeten? ing agents and adsorbent material may be cir-f the partially-or wholly spent metal compounds or mixtures of metal compounds and clay may be withdrawn from the tank 2 and placed in another container and the said slurry intimately contacted with air or oxygen with or without the intimate admixture thereto of hydrochloric acid. It is, however, most advantageous'to reactivate or maintain the activity of the sweetening agents or materials concurrently with the sweetening operation, because it has been found that the rate of regeneration or maintenance of the activity of the sweetening agents is at least as fast as the rate of the sweetening action, that is,- that the rate of regeneration, or maintenance 01 the activity, of the metal compounds or .mixtures of metal compounds and clay does not lag behind the rate of sweetening of the sour constituents, as appears to be the case where large quantities of water are present, and furthermore, the

added oxygen, as'pointed-out above, retards the formation of pellets and also prevents objectionable colorations being produced in the oils treated by the reagents employed.

Instead of contacting the sour oils to be treated with the various reagents employed by agitating" them together by use of the apparatus shown and discribed, the contact between the reagents and the sour oils may be accomplished in any other suitable manner. For example, using cupric chloride and the mixture of cupric chloride and fullers earth as illustrative, these agents may be placed in -a suitable chamber or tower and the sour oils to be sweetened passed through or chloride and clay. When these latter methods of contact are employed the solid reagents are pref-- erably coarser than heretofore described, for example passing through a 30 mesh screen and held on a 60 mesh screen, or passingthrough a 60 mesh screen and held on a 90 mesh screen. Instead of passing the air or oxygen into contact with the mixture of metal compound and clay while the sour oil is being treated by the said mixture,the

flow of the oil may be discontinued and air or oxygen blown or aspirated through the mixture to regenerate it; or regeneration of the mixture may be accomplished by removing the mixture from the apparatus and exposing it to the air, while spread out in thin layers, for a sufflcient time to produce regeneration of it, whereupon the mixture may be used over again to sweeten sour When utilizing the apparatus shown in the accompanying drawingin practicing the invention,

. the metal compounds or mixtures of metal compounds and adsorbent need not be continuously introduced into the apparatus. A batch of metal compound or a mixture 01 metal compound and adsorbent is introduced into the pipe 6 from the hopper I by passages through the pipe 8, under the influence of the centr fugal pump l and after 75 culated in the apparatus shown in the drawing by the introduction of the batch the valve Id in the pipe 8 is closed. The batch so introduced is main tained in continuous circulation in the apparatus in the manner described above in practicing the process.

, As indicated above theprocess in substance I have enumerated a number of metal compounds which may be used, it is to be understood that I do not limit myself to the compounds or agents specifically enumerated, as others are within the scope and principle of my invention. A substantially dry mixture of lead oxide (litharge), sodium hydroxide and adsorbent, for example, fullers earth,'if intimately mixed or contacted with sour gasolene or oil with intimate admixture with the oil of oxygen or air, will sweeten sour oils and the presence or addition of air or oxygen will maintain the sweetening activ ity of the mixture of lead oxide, sodium hydroxide and adsorbent. In this last mentioned instance, the substantially dry mixture of lead oxide, sodium hydroxide and adsorbent may be employed in substantially the same way to sweeten the sour oils as the .clay-cupric. chloride mixture described above, except that no hydrochloric acid isv employed, and no sulphur is required to be added to the oil as is usual in employing sodium plumbite. The litharge and sodium hydroxide may be employed about in the propor-' tions that would form sodium plumbite and the fullers earth may be varied between wide limits, for example the fullers earth may form from 40% to of the mixture. Thus, I do not limit the practice or scope of the invention to any particular agent or mixtures, but the invention includes the use of all agents or mixtures operating within the principle of the invention, whether or not the agents contain components capable of existing in difierent degrees of oxidation or valencies. The terms oxygen" and gaseous oxygen in the appended claims are intended to include, wherever the context permits, oxygen in pure or impure condition, and oxygen gas in admixture with other gases, for

example air, which is a mixture comprising oxygen and nitrogen.

By the terms dry, substantially dry, nonaqueous and similar expressi0n occurring in the specification and claims, I intend to designate solid treating agents and mixtures of treating agents whichmay contain the natural water content oif the-solid adsorbent and/or any normal water of, crystallization of the inorganic salts employed, and waterincidentally formed in the process or taken up from the oil being treated, but wherein the moisture content of the said treating agents or mixtures is not suflicient to cause the formation of an aqueous solution phase, or to cause the formation of a muddy mass with the clay or other adsorbent, as indicated above in the specification. The present application is a continuation in part of my copending applications Ser. No. 494,

973, Ser. No. 508,376 and Ser. No. 539,897.

I claim: r

1. A process of treating sour hydrocarbon oil to sweeten same, which process comprises distributing within a body of the sour hydrocarbon oil, in the presence of gaseous oxygen added thereto, a substantially dry mixture comprising an adsorbent material and a salt of a metal which reacts with mercaptans to form mercaptides and the activity of which is maintained by said oxygen, separating sweetened oil from the mixture comprising the adsorbent material and said salt, and distributing the residual mixture in a further body of sour hydrocarbon oil in the presence of gaseous oxygen added thereto to sweeten said further body of sour hydrocarbon oil.

2.-Process for treating sour hydrocarbon oil to sweeten same, which process comprises agitating the sour hydrocarbon oil with an oxidizing agent and with a solid adsorbent material and a salt of a metal which reacts with mercaptans to form mercaptides, and the activity of which is maintained by said oxidizing agent, the said adsorbent material and salt being in substantially dry form, separating sweetened oil from the said adsorbent material and salt, and agitating a further quantity of sour hydrocarbon oil with the separated adsorbent material and salt and with an additional quantity of the oxidizing agent.

3. Process according to claim 2 in' which the metal salt is a chloride of copper.

4.A process of treating sour hydrocarbon oil to sweeten same, which process comprises distributing within a body of the sour hydrocarbon oil, in the presence of gaseous oxygen added thereto, a substantially dry mixture comprising an adsorbent material and a compound of copper which reacts with mercaptans to form mercaptides and the activity of which is maintained by said oxygen, separating sweetened oil from the mixture comprising the adsorbent material and said compound of copper,-and distributing the residual mixture in a further body of sour hydrocarbon oil in the presence of gaseous oxygen added thereto, to sweeten said further body of sour hydrocarbon ofl.

5. A process of treating sour hydrocarbon to sweeten same, which process comprises distributing within a body of the sour hydrocarbon oil, in the presence of gaseous oxygen added thereto, a substantially dry mixture comprising an adsorbent material and a chloride of copper, separating sweetened oil from the mixture comprising the adsorbent materialand chloride of copper, and distributing the residual mixture in a CHARLES O. HOOVER. 

